1. Field of the Invention
The present invention relates to an imaging apparatus configured to capture of an image of a subject.
2. Description of the Related Art
An optical coherence tomography (OCT) technique using interference of multi-wavelength light enables acquisition of a high-resolution tomographic image of a sample (in particular, a fundus of the eye).
In recent years, an ophthalmologic OCT apparatus can acquire, in addition to a normal OCT image of a shape of a fundus tissue, a polarization-sensitive OCT image using a polarization parameter (i.e., retardation and orientation), which is an optical characteristic of the fundus tissue.
The polarization-sensitive OCT (PS-OCT) can form the polarization-sensitive OCT image using the polarization parameter to be formed, and perform distinguishing and segmentation of the fundus tissue. PS-OCT uses the fact that some layers in the retina (or fundus) of an eye reflect polarized light differently from other layers. International Publication No. WO 2010/122118 A1 discusses a polarization-sensitive OCT which employs a light beam that has been modulated to a circularly-polarized beam as a measuring beam for examining the sample. Detection is then performed by splitting the interference beam into two linearly-polarized beams perpendicular to each other, so that the polarization-sensitive OCT image is generated with different layers in the fundus being imaged differently depending on their interaction with the polarized light.
It is desirable that the imaging apparatus is capable of capturing a polarization-sensitive scanning laser ophthalmoscope (SLO) image in addition to the polarization-sensitive OCT image. In such an imaging apparatus, if a polarization-sensitive OCT optical system and a polarization-sensitive SLO optical system are separately provided, polarization states generated in an image acquired by the polarization-sensitive OCT optical system and an image acquired by the polarization-sensitive SLO optical system may be uneven.